Related Experiment Videos
Psychometric validation of a constipation symptom assessment questionnaire
1Center for Health Outcomes Research, MEDTAP International, Inc., and MEDTAP Systems, LLC, Bethesda, Maryland 20814, USA.
Scandinavian Journal of Gastroenterology
|October 16, 1999
Summary
The PAC-SYM is a reliable and valid tool for assessing constipation symptoms from the patient
Area of Science:
- Gastroenterology
- Clinical Psychology
- Psychometrics
Background:
- Constipation management lacks a gold standard for symptom evaluation.
- The Patient Assessment of Constipation Symptoms (PAC-SYM) instrument was developed.
- Instrument content derived from literature review and focus groups.
Purpose of the Study:
- To psychometrically evaluate the PAC-SYM instrument.
- To assess the validity and reliability of the PAC-SYM.
- To determine the responsiveness of the PAC-SYM to treatment changes.
Main Methods:
- A 6-week psychometric evaluation involving 216 patients across nine sites.
- The final 12-item instrument comprised stool, rectal, and abdominal symptom subscales.
- Psychometric properties including internal consistency, reliability, validity, and responsiveness were assessed.
Main Results:
- High internal consistency (Cronbach's alpha = 0.89) and test-retest reliability (intraclass correlation = 0.75).
- Strong concurrent validity with subject (r=0.68) and investigator (r=0.72) constipation severity ratings.
- The PAC-SYM differentiated between treatment responders and non-responders and showed responsiveness to change over time.
Conclusions:
- The PAC-SYM is a psychometrically sound instrument for constipation symptom assessment.
- It demonstrates internal consistency, reproducibility, validity, and responsiveness.
- PAC-SYM offers a comprehensive method for evaluating constipation treatment effectiveness.